Article Review

Negative Judgments In About Semantic Memory¹
Jhon R. ANDERSON and LYNNE M. REDER
University of Michigan

This result is concered with determining how subjects falsify statements like A collie is a cat. A multiple regersion analysis was performed which used 22 variables to try to predict the negative judgment times. The predictive variables are time to generate the superiordinate of the instance (for example, dog), time to falsify that the superordinate is the predi ate  (for e ample, A dog is a cat), and time to encode theinstance. This finding and others indicate that a prominent negation strategy is one in which the subject generate the superset of an instance anf falsifies that the superset is the predicate. Auxiliary regression analyses are also reported for other reaction time measures gathered in the experiments. It is argued that large-scale regression experiments are critical to the inferential logic of semantic memory experiment.

In the past five years or so, the topic of semantic memory has become a very active area of experimental research. This paper presents a relatively different approach in trying to understand subjects performance in semantic memory tasks. Several of the major theretical analyses in this field are discussed first. We raise some interpretative problems eith earlier studies, and with these considerrations in mind, offer our oen method for investigating the semantic memory parafigm and analtzing its data.
There have been two developments in response to this multiplicity of theories. The first had been the recognition of the diagnostic value of negative judgments. For instance, how do subjects judge a probe like A St. Bernard is a cat or A thypoon is a wheat? The general result is that subjects are slowet the more similar the two concepts or the closer they are in conceptual hierarchy (meyer, 1970; Collins & Quillian, 1972: Smith et al.,in press). Thus subjects are slower in falsifying the first negative example above. This result is completely counter to what collins an Quillian had originally predicted. The result does correspond nicely to the prediction of the similarity model since similar negatives would tend to bias a positive response.

Interpretative problems
The other recent development in semantic memory has been a recognition of the inter-pretative problems posed by the nature of a semantic memory experiment (for example, Anderson & Bowrr, 1973; Clark, 1973; Landauer & Meyer, 1972). The basic problem is that the experimenter cannot randomly construct the material that he will present to his subject.

Summary and conclusions
The primary goal of this paper was to help understand the processes involved in rejecting false categorical statements. Regression analyses were presented using numerous variables to predict the time to reject a categorical statement. Reaction times, rating variables, and frequency norms were used in the prediction of instance negation time. The vatiables found to be critical are the time to generate the superordinate, the time to reject a categorical statements which has the same predicate but use the superordinate rather than the instance, and the time to encode the instance. The prominence of the particular negation strategy found in our experiments is probably due to the logical nature of the task and the fact that negative propositions tend to be stored with large categories.
Another goal of this paper was to call attention to problem in data analyses in most semantic memory tasks. It was pointed out that variables usef in semantic memory studies tend to be correlated and hence confounded. Because one cannot randomly assign materials to condition to test whether certain "variables" affect reaction times, one cannot be certain that the hypothesized vatiables has caused the effect rather than some other known or unknown vatiable related to it.
The present analyses do not tell us anything very critical about the nature of memory. They just identify one prominent falsification strategy.